Wilkinson catalyst synthesis

Scheme 3 Synthesis of Alkylboronates by Hydroboration with Catecholborane and Wilkinsons Catalyst 14-2 1...

AA 24. Mohrig, J.R. Dabora, S.L. Foster, T.F. Schultz, S.C. Stereospecific Synthesis of 2-Deuterio-3-hydroxybutanoate Esters. Regiochemistry and Stereochemistry of Homogeneous Hydrogenation with Wilkinsons Catalyst J. Org. Chem. 1984, 49, 5179-5182... 

In the literature only few publications refer to catalytic reactions of alkenes and carbon dioxide. In 1978 Lapidus and Koryakin investigated the carboxylation of ethene with CO2 and succeeded in the synthesis of propionic acid and ethyl propionate [18,19]. At high pressures (700 atm) and in the presence of the Wilkinson catalyst [RhCl(PPh3)3], which was activated by hydrogen halide promoters, the conversion of ethene reached about 90 % (Equation 2). 

The use of metallocene catalysts revolutionized the synthesis of polyolefins [26]. These catalysts consist of two ring molecules cormected by a metal (Wilkinson catalyst). The two metallocene rings are also sometimes connected by a bridge molecule. The industrial applications of these catalysts was motivated by the discovery by Prof. Kaminsky, who... 

Van Tamelen and coworkers [25] prepared a lanosterol analog via a multistep synthesis (Scheme 8.9). In the last step, the side chain was shortened by the removal of the formyl group with the Wilkinson catalyst. 

Tertiary phosphine complexes [42] are the most important rhodium(I) compounds. RhCl(PPh3)3 ( Wilkinson s compound ), a hydrogenation catalyst, is the most important, but they exist in a range of stoichiometries. Synthesis follows several routes ... 

The modifier in these cases seems to generate enantioselective sites at the metal surface and helps the molecule to adsorb in a preferred fashion so that the formation of only one stereo- product is possible. There are several milestones that have contributed to this state-of-the-art technology. Discovery of Wilkinson s catalyst led to the feasibility of asymmetric hydrogen transfer with the aid of an optically active Wilkinson-type catalyst for L-DOPA (Monsanto s anti-Parkinson disease drug) synthesis (Eqn. (21)). 

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